Trucks of the pick-up style are provided with an open top cargo bed having a bottom or floor surrounded by longitudinal sidewalls with a front wall interconnecting the two sidewalls forming a U-shaped structure. Such cargo beds are also usually provided with a hinged tailgate which, in some instances, may be removed and may be provided with a separate protective liner. The interior surfaces of the cargo bed are invariably subjected to mechanical damage as a consequence of placement of articles within the cargo bed which may, in certain instances, be accomplished in an advertently careless manner as well as a consequence of subsequent shifting or movement of those articles during the course of transit. In those situations where the cargo consists of heavy boxes, tools or other similar items, these have a tendency to scrape the wall surfaces, both side and bottom, and at times to even puncture those walls, thereby at least causing damage to the protective finishes which consequently results in rusting of the sheet metal from which the cargo beds are fabricated as well as detracting from their appearance. To at least minimize if not prevent such damage, it has become a common practice to utilize a liner which is configured to have a bottom wall that overlies the bottom of the bed and sidewalls that extend upwardly adjacent the side and front walls of the cargo bed space. Such a liner may be made of rubber based materials or it may be fabricated from synthetic resin or plastic materials which are molded into a configuration that is complemental to the cargo bed space for a particular model and make of truck.
While a bed liner may be fabricated in a configuration that is complemental to the truck bed cargo space and fits relatively snugly when molded to the dimensional specifications of a particular make and model truck, the liners nevertheless generally require some means for mechanically securing of the liner in the cargo bed. One major reason for securing of the liners is that, especially in the instances when no cargo is being carried, movement of the truck results in airflow over the cargo bed that does have a tendency to lift and move the liners which are not particularly heavy and capable of maintaining themselves in the desired positions. Securing of the liners is particularly important with respect to the vertical sidewalls to avoid having them folded and collapsed into the interior of the cargo bed as a consequence of placing the cargo into the cargo bed through movement over the sides of the bed whereby the cargo may engage the liner and otherwise displace it from its desired vertical position. To assist in maintaining of the sidewalls in a vertical position, it is also a common practice to form the liner sidewalls with extending edges at the upper edges thereof and which overlie and engage with the top rail of the cargo bed. While the overlying flange will tend to support the liner in a desired position, in some instances the flange is fabricated to extend over the outside of the cargo bed rail to better achieve this objective. Merely providing of a flange has not been found to provide sufficient securing of the liner sidewalls to the cargo bed.
Accordingly, in view of the known inability of the liners to be capable of maintaining themselves in the desired position and configuration within a cargo bed, it is a generally accepted practice to also utilize mechanical fastening devices to secure the vertical longitudinally extending sidewalls of the liner to the vertical sidewalls of the cargo bed. It is preferred that these fastening devices be of a type and construction such that it is not necessary to drill holes in the sidewalls or associated structures of the cargo bed since those walls are made of sheet metal and drilling holes would enhance the initiation of rusting. Consequently, fastening devices that have heretofore been utilized have been of a type that either is designed to interfit with existing openings in the truck bed wall or to effect a clamping of the liner to elements of the cargo bed wall. Those devices which utilized openings already formed in the cargo bed have included toggle bolts which have a foldable element that is projected through the openings and therafter opens to effect a clamping function. Examples of openings that are formed in the cargo beds are the sockets into which stakes of the frequently utilized sidewall extensions are inserted. A disadvantage of that type of fastening device is that it then prevents utilization of the stake socket for attachment of sidewall extensions if those should be desired.
Other devices that have been utilized are of a C-type clamp structure which have a component that overlies the outside of the liner and a cooperating element that is placed within the space between the liner and the cargo bed sidewalls and functions to clamp this liner sidewall to the cargo bed sidewall. A problem with such known clamping devices is that they are difficult to install since they have elements that are positioned within a closed space where it is not possible to visually ascertain the location and functioning of the element to assure that it is properly engaged and positioned with respect to the element of the bed sidewall to effect the securing and clamping of the liner. Such clamping devices are also relatively complex in their construction and that complexity adds to their cost.